June 2021
Volume 62, Issue 8
Open Access
ARVO Annual Meeting Abstract  |   June 2021
Measurement of the average group refractive index of the human crystalline lens in vivo using OCT images acquired before and after IOL implantation
Author Affiliations & Notes
  • Marco Ruggeri
    Ophthalmic Biophysics Center, Bascom Palmer Eye Institute, University of Miami School of Medicine, Miami, Florida, United States
    Department of Biomedical Engineering, University of Miami College of Engineering, Coral Gables, Florida, United States
  • Yu-Cherng Chang
    Ophthalmic Biophysics Center, Bascom Palmer Eye Institute, University of Miami School of Medicine, Miami, Florida, United States
    Department of Biomedical Engineering, University of Miami College of Engineering, Coral Gables, Florida, United States
  • Bianca Maceo Heilman
    Ophthalmic Biophysics Center, Bascom Palmer Eye Institute, University of Miami School of Medicine, Miami, Florida, United States
    Department of Biomedical Engineering, University of Miami College of Engineering, Coral Gables, Florida, United States
  • Florence Cabot
    Ophthalmic Biophysics Center, Bascom Palmer Eye Institute, University of Miami School of Medicine, Miami, Florida, United States
    Anne Bates Leach Eye Center, Bascom Palmer Eye Institute, University of Miami School of Medicine, Miami, Florida, United States
  • sonia h yoo
    Ophthalmic Biophysics Center, Bascom Palmer Eye Institute, University of Miami School of Medicine, Miami, Florida, United States
    Anne Bates Leach Eye Center, Bascom Palmer Eye Institute, University of Miami School of Medicine, Miami, Florida, United States
  • Jean-Marie A Parel
    Ophthalmic Biophysics Center, Bascom Palmer Eye Institute, University of Miami School of Medicine, Miami, Florida, United States
    BHVI, Sydney, New South Wales, Australia
  • Fabrice Manns
    Ophthalmic Biophysics Center, Bascom Palmer Eye Institute, University of Miami School of Medicine, Miami, Florida, United States
    Department of Biomedical Engineering, University of Miami College of Engineering, Coral Gables, Florida, United States
  • Footnotes
    Commercial Relationships   Marco Ruggeri, US patent 8,425,037 (P); Yu-Cherng Chang, None; Bianca Maceo Heilman, None; Florence Cabot, None; sonia yoo, None; Jean-Marie Parel, US patent 8,425,037 (P); Fabrice Manns, US patent 8,425,037 (P)
  • Footnotes
    Support  National Eye Institute 2R01EY14225, 1F30-EY027162, and P30EY14801 (Center Core Grant); the Wallace H. Coulter Commercialization Grant (Ruggeri); the Florida Lions Eye Bank and Beauty of Sight Foundation; the Henri and Flore Lesieur Foundation (JMP); Dr HW Flynn Jr, Drs Raksha Urs and Aaron Furtado; Karl R. Olsen, MD and Martha E. Hildebrandt, PhD; an unrestricted grant from Research to Prevent Blindness.
Investigative Ophthalmology & Visual Science June 2021, Vol.62, 2014. doi:
  • Views
  • Share
  • Tools
    • Alerts
      ×
      This feature is available to authenticated users only.
      Sign In or Create an Account ×
    • Get Citation

      Marco Ruggeri, Yu-Cherng Chang, Bianca Maceo Heilman, Florence Cabot, sonia h yoo, Jean-Marie A Parel, Fabrice Manns; Measurement of the average group refractive index of the human crystalline lens in vivo using OCT images acquired before and after IOL implantation. Invest. Ophthalmol. Vis. Sci. 2021;62(8):2014.

      Download citation file:


      © ARVO (1962-2015); The Authors (2016-present)

      ×
  • Supplements
Abstract

Purpose : Knowledge of the average refractive index of the human crystalline lens along its optical axis is useful to obtain accurate estimates of the lens thickness and posterior lens shape with OCT (Borja et al, Biomed Opt Express 2010). We present a method for measuring the average group refractive index of the lens by acquiring OCT images in patients before and after cataract surgery.

Methods : Eighteen eyes from 13 patients (age 73.5 ± 5.3 years) who underwent cataract surgery and IOL implantation at Bascom Palmer Eye Institute were imaged with an extended depth SD-OCT system at 840 nm (Ruggeri et al, Biomed Opt Express 2012) before and one to six months after surgery. All surgeries were performed by one of two surgeons using standard monofocal IOLs (Acrysof, Alcon). Optical path lengths of the anterior chamber, crystalline lens, IOL and vitreous were measured in the pre- and post-operative images of all eyes using custom-made software (MATLAB). Except for the crystalline lens, all intraocular optical lengths were converted to geometrical distances using the group refractive indices at 840 nm of the aqueous and vitreous (nAQ = nV = 1.341; Ruggeri et al Biomed Opt Express 2012) and of the IOL (nIOL = 1.601), which was measured on a non-sterile IOL sample using the method of Uhlhorn et al (Vis. Res. 2008). For each eye, the geometrical thickness of the lens was calculated from the pre- and post-operative geometrical distances assuming that axial eye length does not change after surgery. The average group refractive index of the lens was then calculated as the ratio between the optical and geometrical lens thickness.

Results : The average group refractive indices of all crystalline lenses are summarized in the table, giving an overall average of 1.425 ± 0.009 mm (range: 1.413 – 1.439), which is comparable to the group refractive index measured with OCT in vitro (1.416 ± 0.004; Uhlhorn et al Vis. Res. 2008).

Conclusions : The study demonstrates the feasibility of measuring the average axial group refractive index of the crystalline lens in vivo by quantifying ocular distances before and after IOL implantation.

This is a 2021 ARVO Annual Meeting abstract.

 

×
×

This PDF is available to Subscribers Only

Sign in or purchase a subscription to access this content. ×

You must be signed into an individual account to use this feature.

×